The term "competent" refers to

Options

A. 1) increasing the competition between cells
B. 2) making cells impermeable for DNA
C. 3) increasing the efficiency with which DNA enters the bacterium through pores in its cell wall
D. 4) making cells permeable for divalent cations

Explanation

To understand the term "competent" in the context of biotechnology, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Definition of Competent Cells**:
- The term "competent" refers to the ability of a cell to take up foreign DNA from its environment. This is a crucial step in genetic engineering and molecular biology.

2. **Importance of Competence**:
- For a cell to incorporate foreign DNA, it must be able to allow that DNA to pass through its cell membrane. This is not a natural process for many cells, particularly bacteria.

3. **Mechanism of Competence**:
- Competent cells have been treated or manipulated to create pores in their cell walls. These pores allow the foreign DNA to enter the cell more efficiently.

4. **Options Analysis**:
- The question provides several options regarding what "competent" refers to:
- **Option 1**: Increasing competition between cells - This is incorrect as it does not relate to DNA uptake.
- **Option 2**: Making cells impermeable for DNA - This is also incorrect as it contradicts the concept of competence.
- **Option 3**: Increasing the efficiency with which DNA enters the bacterium through pores in its cell wall - This is correct as it directly describes the process of making a cell competent.
- **Option 4**: Making cells permeable for divalent cations - This is not the primary definition of competent cells.

5. **Conclusion**:
- The correct interpretation of "competent" in this context is best represented by **Option 3**: "increasing the efficiency with which DNA enters the bacterium through pores in its cell wall."

### Final Answer:
The term "competent" refers to increasing the efficiency with which DNA enters the bacterium through pores in its cell wall (Option 3).

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